Watchdog cleanup (#15283)

Marlin/src/HAL/HAL_LINUX/watchdog.cpp

@@ -29,18 +29,8 @@
 #include "watchdog.h"
 
 void watchdog_init() {}
+void HAL_watchdog_refresh() {}
 
-void HAL_clear_reset_source() {}
-
-uint8_t HAL_get_reset_source() {
-  return RST_POWER_ON;
-}
-
-void watchdog_reset() {}
-
-#else
-  void HAL_clear_reset_source() {}
-  uint8_t HAL_get_reset_source() { return RST_POWER_ON; }
-#endif // USE_WATCHDOG
+#endif
 
 #endif // __PLAT_LINUX__